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Abstract:

A device for driving a plurality of fasteners includes a driver assembly
having a drive block, a flywheel and a driver mount. The driver mount is
configured to move between a first position where the flywheel is removed
from the drive block and a second position where the flywheel engages the
drive block. The device also includes a work contact element configured
to move between an extended position and a depressed position. A blocking
arm is connected to the work contact element and configured to move with
the work contact element. The blocking arm is positioned in a path of
movement of the driver mount when the work contact element is in the
extended position. The blocking arm is removed from the path of movement
of the driver mount when the Work contact element is in the depressed
position.

Claims:

1. A device for driving a plurality of fasteners, the device comprising:a
magazine configured to retain the plurality of fasteners;a driver
assembly configured to provide an expulsion force that expels one of the
plurality of fasteners from the magazine, the driver assembly including a
driver member configured to move along a path between a first position
where the driver assembly is prevented from providing an expulsion force
and a second position where the driver assembly is configured to provide
the expulsion force;a work contact element moveable in a linear direction
between an extended position and a depressed position; anda blocking
member connected to the work contact element and configured to move in
the linear direction when the work contact element is moved in the linear
direction, wherein the blocking member is positioned in the path of
movement of the driver member and blocks the driver member from moving to
the second position when the work contact element is in the extended
position.

2. The device of claim 1 wherein the blocking member is configured to move
out of the path of movement of the driver member when the work contact
element is in the depressed position.

3. The device of claim 2 further comprising a trigger and an actuator, the
trigger moveable between a release position and a fire position, and the
actuator configured to urge the driver member toward the second position
when the trigger is moved from the release position to the fire position.

4. The device of claim 3 wherein the actuator is a solenoid configured to
contact a surface of the driver member.

5. The device of claim 1 wherein the driver member comprises a driver
mount, wherein a flywheel is removed from a driver block when the driver
mount is in the first position, and wherein the flywheel engages the
driver block when the driver mount is in the second position.

6. The device of claim 5 wherein the blocking member comprises a blocking
arm.

7. The device of claim 6 wherein the blocking arm comprises at least one
finger configured for insertion into a slot in the driver mount when the
work contact element is in the depressed position and the driver mount is
moved from the first position to the second position.

8. The device of claim 5 wherein the flywheel is positioned on the driver
mount.

9. A device for driving a plurality of fasteners, the device comprising:a
driver assembly including a drive block, a flywheel and a driver mount,
the driver mount configured to move between a first position where the
flywheel is removed from the drive block and a second position where the
flywheel engages the drive block;a work contact element moveable between
an extended position and a depressed position; anda blocking arm
connected to the work contact element and configured to move with the
work contact element, wherein the blocking arm is positioned in a path of
movement of the driver mount when the work contact element is in the
extended position and blocks the driver mount from moving to the second
position, and wherein the blocking arm is removed from the path of
movement of the driver mount when the work contact element is in the
depressed position such that the driver mount is free to move to the
second position.

10. The device of claim 9 wherein the flywheel is rotatably mounted on the
driver mount.

11. The device of claim 9 wherein the driver assembly further comprises an
actuator configured to urge the driver mount toward the second position
when a trigger is pulled.

12. The device of claim 11 wherein the blocking arm includes a blocking
surface configured to engage the driver mount when the trigger is pulled
and the work contact element is in the extended position.

13. The device of claim 12 wherein the blocking surface of the blocking
arm is configured to avoid engagement with the driver mount when the
trigger is pulled and the work contact element is in the depressed
position.

14. The device of claim 11 wherein the actuator is a solenoid.

15. The device of claim 9 wherein the blocking arm includes a finger
dimensioned to fit in a slot on the blocking arm when the driver mount
moves from the first position to the second position.

16. A device for driving a plurality of fasteners, the device comprising:a
driver assembly including a drive block, a flywheel and a driver mount,
the driver mount configured to move between a first position where the
flywheel is removed from the drive block and a second position where the
flywheel engages the drive block, the driver mount including a first
blocking surface;a work contact element moveable between an extended
position and a depressed position; anda blocking arm connected to the
work contact element and configured to move between a blocking position
when the work contact element is in the extended position and a pass-by
position when the work contact element is in the depressed position, the
blocking arm including a second blocking surface, wherein the second
blocking surface is configured to engage the first blocking surface of
the driver mount and block the driver mount from moving from the first
position to the second position when the work contact element is in the
extended position, and wherein the second blocking surface is configured
to avoid engagement with the first blocking surface when the work contact
element is in the depressed position.

17. The device of claim 16 wherein the second blocking surface of the
blocking arm is provided on a finger of the blocking arm configured to
fit within a slot on the driver mount when the blocking arm is in the
pass-by position.

18. The device of claim 16 wherein the second blocking surface of the
blocking arm is provided on a finger of the blocking arm configured to
engage a surface of the driver mount when the blocking arm is in the
blocking position.

19. The device of claim 16 wherein the flywheel is rotatably positioned on
the driver mount.

20. The device of claim 16 wherein the driver assembly further comprises
an actuator configured to urge the driver mount toward the second
position when a trigger is pulled.

Description:

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001]This application is a continuation-in-part of U.S. patent
application Ser. No. 12/559,724, filed Sep. 15, 2009, the contents of
which are incorporated herein by reference.

FIELD

[0002]This application relates to the field of power tools and
particularly to devices used to drive fasteners into work-pieces.

BACKGROUND

[0003]Fasteners such as nails and staples are commonly used in projects
ranging from crafts to building construction. While manually driving such
fasteners into a work piece is effective, a user may quickly become
fatigued when involved in projects requiring a large number of fasteners
and/or large fasteners to be driven into a work piece. Moreover, proper
driving of larger fasteners into a work piece frequently requires more
than a single impact from a manual tool.

[0004]In response to the shortcomings of manual driving tools,
power-assisted devices for driving fasteners into work pieces have been
developed. Contractors and homeowners commonly use such devices for
driving fasteners ranging from brad nails used in small projects to
common nails which are used in framing and other construction projects.
Compressed air has been traditionally used to provide power for the
power-assisted (pneumatic) devices. However, other power sources have
also been used, such as DC motors.

[0005]Various safety features have been incorporated into pneumatic and
other power nailers. One such device is commonly referred to as a work
contact element (WCE). A WCE is incorporated into nail gun designs to
prevent unintentional firing of the nail gun. A WCE is typically a spring
loaded mechanism which extends outwardly from the portion of the nail gun
from which a nail is driven. In operation, the WCE is pressed against a
work piece into which a nail is to be driven. As the WCE is pressed
against the work piece, the WCE compresses the spring and generates an
axial movement which is transmitted to a trigger assembly. The axial
movement is used to reconfigure a safety device, which is typically a
trigger disabling mechanism, so as to enable initiation of a firing
sequence with the trigger of the nail gun.

[0006]Since typical WCE arrangements in the past have included a
mechanical linkage between the WCE and the trigger, it would be
advantageous to provide an additional safety feature that is not
necessarily linked with trigger operation. It would also be advantageous
if such safety feature interacted with the firing mechanism to block
operation of the firing mechanism if the WCE is not depressed.

SUMMARY

[0007]In accordance with at least one embodiment, a device for driving a
plurality of fasteners includes a magazine configured to retain the
plurality of fasteners and a driver assembly configured to provide an
expulsion force that expels one of the plurality of fasteners from the
magazine. The driver assembly includes a driver member configured to move
along a path between a first position where the driver assembly is
prevented from providing an expulsion force and a second position where
the driver assembly is configured to provide the expulsion force. The
device further includes a work contact element and a blocking member
connected to the work contact element. The work contact element is
moveable in a linear direction between an extended position and a
depressed position. The blocking member is configured to move in the
linear direction when the work contact element is moved in the linear
direction. When the work contact element is in the extended position, the
blocking member is positioned in the path of movement of the driver
member and blocks the driver member from moving to the second position.

[0008]In at least one embodiment, a device for driving a plurality of
fasteners includes a driver assembly having a drive block, a flywheel and
a driver mount. The driver mount is configured to move between a first
position where the flywheel is removed from the drive block and a second
position where the flywheel engages the drive block. The device also
includes a work contact element configured to move between an extended
position and a depressed position. A blocking arm is connected to the
work contact element and configured to move with the work contact
element. The blocking arm is positioned in a path of movement of the
driver mount when the work contact element is in the extended position
and blocks the driver mount from moving to the second position. The
blocking arm is removed from the path of movement of the driver mount
when the work contact element is in the depressed position such that the
driver mount is free to move to the second position.

[0009]In at least one embodiment, a device for driving a plurality of
fasteners comprises a driver assembly including a drive block, a flywheel
and a driver mount with a first blocking surface. The driver mount is
configured to move between a first position where the flywheel is removed
from the drive block and a second position where the flywheel engages the
drive block. A work contact element is moveable between an extended
position and a depressed position. A blocking arm is connected to the
work contact element and configured to move between a blocking position
when the work contact element is in the extended position and a pass-by
position when the work contact element is in the depressed position. The
blocking arm includes a second blocking surface that is configured to
engage the first blocking surface of the driver mount and block the
driver mount from moving from the first position to the second position
when the work contact element is in the extended position. The second
blocking surface is further configured to avoid engagement with the first
blocking surface when the work contact element is in the depressed
position and the driver mount is moved from the first position to the
second position.

BRIEF DESCRIPTION OF THE DRAWINGS

[0010]FIG. 1 depicts a side perspective view of an exemplary embodiment of
a fastener driver with a driver assembly blocking member;

[0011]FIG. 2 depicts a cutaway side view of the nose assembly of the
fastener driver of FIG. 1 with a work contact element in an extended
position and coupled to a lockout assembly and a depth adjustment
mechanism;

[0012]FIG. 3 depicts a cutaway side view of the nose assembly of the
fastener driver of FIG. 1 with the work contact element in a
depressed/retracted position;

[0013]FIG. 4 depicts a perspective view of the work contact element
assembly isolated from the other elements of FIG. 2;

[0014]FIG. 5 depicts a perspective view of the depth adjustment mechanism
isolated from the other elements of FIG. 2;

[0015]FIG. 6 depicts a perspective view of a lockout and blocking assembly
isolated from the other elements of FIG. 2;

[0016]FIG. 7 depicts a perspective view of the work contact element
assembly connected to the depth adjustment mechanism of FIG. 5 and the
lockout and blocking assembly of FIG. 6;

[0017]FIG. 8 shows a cutaway side view of a blocking arm of the lockout
and blocking assembly of FIG. 7 positioned in the fastener driver in
association with a pivoting driver mount;

[0018]FIG. 9 shows an enlarged view of the blocking arm of FIG. 8 when the
work contact element is in an extended position;

[0019]FIG. 10 shows the blocking arm of FIG. 9 when the work contact
element is in a depressed position;

[0020]FIG. 11 shows an isolated perspective view of the lockout and
blocking assembly of FIG. 7 in relation to the pivotable driver mount
when the work contact element is in the extended position;

[0021]FIG. 12 shows a perspective view of the lockout and blocking
assembly of FIG. 11 when the work contact element is in the depressed
position; and

[0022]FIG. 13 shows a perspective view of the lockout and blocking
assembly of FIG. 12 with the pivotable driver mount moved to a second
position.

DESCRIPTION

[0023]FIG. 1 depicts one embodiment of a device 100 for driving a fastener
including a drive housing 102 and a fastener storage and feeding device
104. The term "magazine" is also used herein to refer to any such device
used to store and/or feed fasteners, such as for example, the feeding
device 104 shown in FIG. 1. The drive housing 102 defines a handle
portion 106 from which a trigger 108 extends, a receptacle area 110 and a
drive section 112. The fastener guide 104 in this embodiment is spring
biased to force fasteners, such as nails or staples held in a cartridge
or a clip, serially one after the other, into a loaded position adjacent
the drive section 112. The receptacle area 110 may be used to connect a
source of compressed air or other source of power (such as a battery) to
the fastener driver device 100.

[0024]Located adjacent to the drive portion 112 and the magazine 104 is a
nose assembly 114. FIG. 2 shows a cutaway view of the nose assembly 114,
the lower part of the drive portion 112, and an end portion of the
magazine 104. The nose assembly 114 includes a work contact element (WCE)
120 configured to slide along a nose frame 118 which is fixed to the
housing 102. The WCE 120 is configured to slide relative to the housing
102 and nose frame 118 between an extended position, as shown in FIG. 2,
and a retracted/depressed position, as shown in FIG. 3. As mentioned
previously, although the term WCE is used herein to refer to such safety
devices that move when contacted with a work piece, it will be recognized
that other names are commonly used for the WCE, such as a "contact trip".

[0025]As best shown in the isolation view of FIG. 4, the WCE 120 is
connected to a WCE arm 130 to form the WCE assembly 121. In this
embodiment, the WCE 120 is provided as a wireform bent in a shape such
that a blunt contact tip 122 is formed between the two ends 124 and 126
of the wireform. One end 126 of the wireform is inserted in a slot 132 in
the WCE arm 130 in order to rigidly connect the WCE 120 to the WCE arm
130.

[0026]With continued reference to FIG. 4, the WCE arm 130 includes a
circular guide 134 on an end of the arm 130 opposite the slot 132. The
circular guide 134 defines a hole 136 and the interior of this hole 136
is threaded. An opening 138 is also formed on the circular guide end of
the WCE arm 130.

[0027]With reference now to the embodiment of FIGS. 2 and 5, the WCE
assembly 121 is coupled to the depth adjustment mechanism 141. The depth
adjustment mechanism 141 comprises a dial 156 (see FIG. 2) connected to a
sleeve 140 that is rotatably positioned on a center rod 142. The center
rod 142 includes a first cylindrical portion 144 connected to a second
cylindrical portion 150. The second cylindrical portion 150 has a greater
diameter than the first cylindrical portion 144 such that a shoulder is
formed between the first portion 144 and the second portion 150. The
center rod 142 also includes a neck 152, and a head 154.

[0028]The sleeve 140 is rotatably positioned on the center rod 142 with
the first cylindrical portion 144 of the center rod 142 extending
completely through the sleeve 140. The sleeve 140 includes a cylindrical
threaded segment 146 and a polyhedron segment 148. The dial 156 is
slideably mounted on the polyhedron segment 148. The dial 156 is disc
shaped with a knurled perimeter. This allows a user to easily rotate the
dial 156. Rotation of the dial 156 results in rotation of the sleeve 140
relative to the center rod 142.

[0029]The threaded segment 146 of the sleeve 140 is inserted through the
circular guide 134 of the WCE arm 130 and threadedly engages the circular
hole 136 of the WCE arm 130. Accordingly, rotation of the dial 156 and
sleeve 140 results in linear (i.e., axial) movement of the WCE arm 130 as
the threads on the circular guide 134 of the WCE assembly engage the
complimentary threads of the threaded segment 146 of the sleeve 140.

[0030]With reference now to FIGS. 2 and 6, the depth adjustment mechanism
141 is rotatably coupled to a lockout and blocking assembly 161. As best
seen in the isolated view of FIG. 6, the lockout and blocking assembly
161 includes a lockout member 160 and a blocking member 170. As explained
in further detail below, the lockout member 160 is configured to prevent
the WCE 120 from being depressed when the magazine 104 is empty or
substantially empty of fasteners. As also explained in further detail
below, the blocking member is configured to prevent the driver assembly
from actually firing a fastener if the WCE 120 is not depressed.

[0031]In the embodiments disclosed herein, the lockout member 160 is
provided as an arm that pivots relative to the WCE assembly 121 about a
pivot shaft 166. Accordingly, the lockout member may be referred to
herein as a "pivot arm" 160. The blocking member 170 is provided as an
arm that is connected to the WCE assembly 121 in a non-pivoting manner.
Accordingly, the blocking member may be referred to herein as a "blocking
arm" 170. The pivot arm 160 and blocking arm 170 are both configured to
move in a linear direction along with the WCE 120 when the WCE moves
between the extended position and the depressed position.

[0032]The blocking arm 170 includes a body portion 172 with an elbow 174
extending from the body portion 172. The elbow 174 is connected to an
extension portion 176 that protrudes outward from the body portion 172 in
a generally perpendicular manner. Two blocking fingers 178 are positioned
on the extension portion 176. The blocking fingers 178 protrude outward
from the extension portion 176 in a generally perpendicular manner. When
the device 100 is assembled as shown in FIGS. 4 and 7, one of the
blocking fingers 178 extends through the opening 138 in the WCE assembly
121. As explained in further detail below, the tips 179 of the fingers
178 provide surfaces that prevent parts of a driver assembly 200 (see
FIG. 8) from moving and providing an expulsion force that fires a
fastener out of the device 100.

[0033]The blocking arm 170 also includes a bore (not show) that is
configured to receive the end of the first cylindrical portion 144 of the
center rod 142 of the depth adjustment mechanism 141. The end of the
first cylindrical portion 144 of the depth adjustment mechanism 141 is
secured in the bore of the blocking arm 170 such that the center rod 142
is fixedly connected to the blocking arm 170. The sleeve 140 of the depth
adjustment mechanism 141 is rotatably trapped on the center rod 142
between the blocking arm 170 and the second cylindrical portion 150 of
the center rod 142. In this manner, the sleeve 140 of the depth
adjustment mechanism 141 is rotatably coupled to the lockout and blocking
assembly 161. Furthermore, because the WCE assembly 121 is coupled to the
depth adjustment mechanism 141, the WCE assembly 121 is therefore also
coupled to the lockout and blocking assembly 161, as can be seen with
reference to FIG. 7.

[0034]With reference again to FIG. 6, the lockout arm 160 is pivotably
connected to the blocking arm 170 about the pivot shaft 166. Accordingly,
one end of the lockout arm 160 includes a hole that allows the pivot
shaft 166 to pass through the lockout arm 160. The opposite end of the
lockout arm includes a foot 162 configured to move between a fire
position and a lockout position, wherein the foot includes a surface that
engages the WCE 120 and blocks the WCE from depressing when in the
lockout position. The foot 162 moves to the lockout position when the
magazine is low on fasteners.

[0035]The lockout arm 160 is pivotable between a rearward "unlocked"
position, as shown in FIGS. 2 and 3, and a forward "locked" position, as
shown in FIGS. 7 and 8. A spring 168 is mounted on the pivot shaft 166
and biases the lockout arm 160 toward the unlocked position of FIGS. 2
and 3. A spring loaded follower 158 in the magazine 104 forces fasteners
toward the nose 114.

[0036]In operation, the WCE assembly 121, lockout and blocking assembly
161, and depth adjustment mechanism 141 are all coupled together and work
as a unit to provide various features for the device 100. FIGS. 2 and 3
generally show operation of these components when the WCE 120 is moved
from the extended position to the retracted position. In FIG. 2, the WCE
120 is in an extended position. When the WCE 120 is moved from the
extended position shown in FIG. 2 to the retracted position shown in FIG.
3, the WCE arm 130 moves with the WCE 120 and is retracted in a linear
direction into the driver housing 102. The WCE arm 130 is coupled to the
sleeve 140 of the depth adjustment mechanism and thus, the sleeve 140 is
also moved along with the WCE arm 130. When the sleeve 140 is moved in
the linear direction, the blocking arm 170, pivot shaft 166, and pivot
arm 160 of the lockout and blocking assembly 161 are also moved in the
linear direction. Because the pivot arm 160 is in an unlocked position in
FIG. 3 the foot 162 of the pivot arm 160 avoids a flange 116 that is
positioned in the nose 114 and fixed in relation to the housing 102. In
particular, the foot 162 of the pivot arm 160 is allowed to move past the
flange 116 as the WCE 120 is moved to the depressed position. When the
pivot arm 160 and connected blocking arm 170 are allowed to move past the
flange, the blocking finger 178 is moved to a position that does not
block firing of the device 100, as explained in the following paragraphs
with reference to FIGS. 8-10.

[0037]FIG. 8 shows a side view of the fastener device 100 in order to
provide an explanation of the general operation of the device 100. As
shown in FIG. 8, the device 100 includes a driver assembly 200 including
a DC motor 202, a flywheel 204, a drive block 206, a drive blade 208. The
flywheel 204 is positioned on a pivotable drive mount 210 (outlined with
dotted lines in FIG. 8) and the flywheel is configured to rotate on the
mount about axis 211. The mount 210, in turn, is configured to pivot
about a pivot point 212. An actuator in the form of solenoid 214 is
configured to engage the drive mount 210 and urge it to move along a
pivot path 224 between a first position where the flywheel 204 is removed
the drive block 206 and a second position where the flywheel 204 engages
the drive block 206. The mount 210 is generally biased (e.g., spring
biased) toward the first position and the actuator 214 encourages
movement toward the second position.

[0038]In operation, a user brings the WCE 120 into contact with a work
piece and then pulls the trigger 108 in order to fire a fastener from the
device. When the user pulls the trigger 108, the DC motor 202 is
energized and transmits power to the flywheel 204 via a drive belt. After
a predetermined flywheel speed has been reached, the solenoid 214 is
energized. When the solenoid 214 is energized, a plunger 216 associated
with the solenoid 214 is moved into contact with the mount 210. The
moving plunger 216 then forces the mount 210 and rotating flywheel 204 to
pivot toward the drive block 206. When the rotating flywheel 204 comes
into contact with the drive block 206, the drive block 206 and connected
drive blade 208 are propelled toward the nose. When the drive block 206
and blade 208 are fired, drive blade 208 impacts the fastener positioned
at the end of the magazine 104 and expels the fastener from the device
100. A similar arrangement is disclosed in U.S. patent application Ser.
No. 12/191,960, the contents of which are incorporated herein in their
entirety. Furthermore, although the driver assembly of FIG. 8 includes a
DC motor and flywheel, it will be recognized that any of various other
drive assemblies are possible.

[0039]With particular reference now to FIGS. 9-12, the blocking arm 170
provides a safety feature for the device 100 which prevents the device
from firing when the WCE 120 is in the extended position. As shown in
FIGS. 9 and 11, when the WCE 120 is in the extended position, the fingers
178 of the blocking arm 170 are positioned in a blocking position that
interferes with the pivot path of the mount 210. Thus, if the user pulls
the trigger with the WCE 120 in the extended position, the solenoid
plunger 216 will contact the mount 210 and urge the mount to move in the
direction of arrow 230. However, when this occurs, the tips 179 of the
fingers 178 will contact a surface 222 on the driver mount 210 and block
the mount 210 from pivoting further toward the drive block 206.
Accordingly, when the blocking arm 170 is in the blocking position, the
flywheel is prevented from coming into contact with the drive block 206,
and the device 100 is blocked from expelling a fastener.

[0040]FIG. 12 shows the position of the blocking arm 170 relative to the
mount 210 when the WCE 120 is in the depressed position, but the user has
not pulled the trigger 108. In particular, when the WCE 120 is depressed,
the blocking arm 170 moves in a linear direction (as indicated by arrow
240 in FIG. 12) to a pass-by position where the locking arm will not
interfere with the mount 210 when it pivots along the pivot path. In the
embodiment of FIG. 12, the fingers 178 of the blocking arm 170 are
aligned with slots 226 in the mount 210 when the locking arm is in the
pass-by position. The slots 226 in the mount 210 are designed and
dimensioned to receive the fingers 178 such that the fingers 178 will fit
into the slots without contacting the mount 210.

[0041]With the blocking arm 170 in the pass-by position of FIG. 12, the
user may then pull the trigger 108, causing the actuator 214 to urge the
mount 210 along the pivot path. As shown in FIGS. 10 and 13, when the
mount 210 is moved along the pivot path in the direction indicated by
arrow 230, the fingers 178 of the locking arm 170 are inserted into the
slots 226 in the mount 210, allowing the mount to move the full distance
of the pivot path. Thus, when the locking arm 170 is in the pass-by
position, it does not interfere with movement of the mount 210, and the
flywheel 204 (which is rotatably positioned on the mount 210) may be
moved into contact with the driver block 206, causing the device 100 to
fire.

[0042]While the fastener driver with lockout arm has been illustrated and
described in detail in the drawings and foregoing description, the same
should be considered as illustrative and not restrictive in character. It
is understood that only the preferred embodiments have been presented and
that all changes, modifications and further applications that come within
the spirit of the invention are desired to be protected.